The present invention relates to a vehicle bumper construction and an apparatus and method for manufacturing the same. More particularly, the present invention relates to a roll-formed bumper having a predetermined section with foam-in-place material, and a method and apparatus for making the same.
Recently, a novel roll-formed tubular bumper construction was made as disclosed in Sturrus et al. U.S. Pat. No. 5,092,512 issued Mar. 3, 1992, entitled METHOD OF ROLL-FORMING AN AUTOMOTIVE BUMPER. The novel roll-formed tubular bumper construction has been well received commercially due to the potential cost and weight savings gained over conventional stamped bumpers. However, further improvements in the bumper construction and the apparatus and method for making same are desired so that even greater cost and weight savings are attainable.
One practical reason limiting the choice and thickness of materials in roll-formed tubular bumper constructions are the bumper impact tests required by Federal Motor Vehicle Safety Standards (FMVSS). Specifically, the FMVSS include a pole test and a pendulum test conducted at the center of the front bumper between the bumper-to-vehicle attachment brackets that place a high localized load at the center of the bumper. In conventional bumpers, the center section of the bumper can be specially configured to pass these tests. However, roll-forming processes are not suited for making a specially configured center section. Thus, any means for localized support in this center section must come from secondary operations, or the whole roll-formed tubular bumper construction must be strengthened.
It is known to fill a bumper with foam-in-place material to provide improved strength and improved stress distribution. However, a bumper filled with foam material tends to be unacceptably heavy. Further, the volume of foam material used unacceptably adds to cost. Still further, there is a lack of apparatus and methods for filling bumpers with foam material in an automated manner.
Thus, improvements solving the aforementioned problems are desired in the article, apparatus, and method.